Method of manufacturing iron.



No. 889,125. I v I 4PATENTED MAY 26, 1908. H. L. HARTENSTEIN.

METHOD OFMANUPAGTURING IRUN. APPLIGATION FILED JULY 19. 1907.

2 SHEET-SEEETL H. L. HARTBNSTEIN.

METHOD 0F MANUFACTURING IRON.

.APPLICATION FILED JULY19. 1907.

PATENTED MAY r26, 1908.

2 SHEETB--SHEET 2.

UNITED srarsgigngnnr oiuuon.

HERMAN L. HARTENSTEIN, 0l" CONSTANTINE, MICHIGAN, ASSIGNOR. TO ELECTRO CHEM- IOAL & DEVELOPMENT. GO., OI"

DAKOTA.

METHOD OF MANUFACTURING IRON.

Specification of Letters Patent.

Patented May 26, 1908.

Original application filed March 9, 1907, Serial No. 361,632. Divided and' this application filed July 19, 1907.

' Serial No. 384,568. I

To all whom it 'ma/y concern:

Be it known that I, HERMAN L. IIARTEN- s'TEIN, a citizen of the United States, residing at Constantine, in the county if-St.

Joseph'and State of Michigan, have inventedl vcertain new and useful Improvements in the Method of Manufacturing Iron, of which the following is ay full, clear, and exact specification.

This invention relates to improvements in the manufacture of iron, and has more cs-v pccial reference to the utilization of certain waste products heretofore occurring in that lndustry.

At the present time the greaterportion or a large percentage ofthe iron ore used in the inamlfarturc of iron is of the softer natures, such as the Mesaba ore, and which, o\ ving to its tendency to crumble and to other peculiarities of structure, is reduced in great part-during handling and crushing to a very `line state of subdivision. When the furnace 1s subjected to the necessary high pressure for successfully blowing it a large percentage of this fine ore or material is blown out of the smelter and in fact cannot be retained therein, but is caught or settles in the dust chamber, from which it is removed at intervals. The value of. the fine material thus ejected from a furnace is ,quite a desideratuin, as it amountsto from five to ten per cent. of the entirequantity of ore placed in the blast furnace. Heretofore unsuccessful efforts have been made to recover and utilize this Waste, but as they consist mainly inattem ts to form the waste into bricks or blocks lb'y compressing it with binders or adhesives and then drying or baking the blocks, which arev afterwards charged into the furnace with the other ore, fuel and fluxing materials, it'is obvious that these prior methods r`add so I greatly to the expense of the final .product `as to make` them of but little value'. As a consequence, manufacturers generally regard this fine ore which discharges from the furnace as a total'waste and remove it-and discard it with as small an expenditure of time and labor as possible. Itis also well known that in themanufactu re of iron where, blast furnaces are employed which use solid fuel such as coal" and coke, a large amount of the coalvand coke, and particularly the coke, which is delivered to them for use is a total seriously interfere with the proper operation V thereof and the consequent reduction in its output. This fine fuel, therefore, is also discarded like the dust or fine particles of ore which are carried off in the blowing operation.

The object of my present invention, therefore, is to utilize all or any of these waste materials, and to produce therefrom a valuable grade of iron at Ininimum cost.

With these ends in View, the invention consists in the features of novelty which will now be described more fully and with reference to the accompanying drawings, showing a suitable apparatus for carrying' the method into 'ell'ee/t, and will then be particularly pointed out in the claims. 4

ln the said draWings,-Figure 1 is a diagrammatic illustration of an apparatus utilized inf-the performance of this method, showing the apparatus in side elevation. Fig. 2 is an enlarged detail view partlyin section of a portion of a eonveyer hereinafter described. Fig. 3 is a diagrammatic plan View of the apparatus, and rig. 4 is a vertical longitudinal sectionalview of one end of the rotating furnace 0n an enlarged scale.

In carrying out the invention, I mix from 500 to 700 pounds, approximately speaking, of the waste coal or coke before referred to' to every ton of metallic iron contained in the flue dust, which as is understood, is the fine ore that discharges from the furnace without being converted, the amount of metallic iron in such dust being of course ascertained by proper analysis. This mixture of fuel and flue dust is then fed into a suitable furnace, where it 4is subjected to sufficient heat to cause the carbon of the carbonaceo'us material or fuel to combine with the oxygen ofthe flue dust, thereby resulting in a goed grade of iron which is in the-form of sponge. This iron sponge -may be utilized in the manu facture of iron and steel and in open hearth pudd'ling, electric, Bessemer, or any other steel or iron manufacturing processes acwasted and the resultant iron or steel in the production of which the sponge was utilized may be chea ened, yet if desired the sponge may be with rawn from the furnace and permitted to cool and then transported to places where required for use in-the manufacture of other products, but in the event it be allowed to cool before it is thus used it should be converted into blooms, slabs, billets, or other solid forms by passin it between r-olls, screw bars, or hammers whi e it is still heated to prevent oxidation which readily occurs when exposed to the atmosphere. It is, of course, obvious also that while my present invention is primarily designed for the utili- 'zation-of the heretofore waste products before referred to, iron ore mixed with carbonaceous material such as described if reduced to this finestate even artificially, may

be economically and advantageously converted into metallic iron by my described process, as will hereinafter more fully appear.

Referring to the apparatus, 1 is a rotary kiln such as might be employed in calciniiig limestone, Vand which is sup brted on suitable bearings 2, 3, and provi( ed with a gear 4, capable of being driven by a pinion 5 on shaft `6 from any suitable source of power. At the lower end of the rotary cylinder 1 is arranged a fixed or non-rotary hearth 7,

which serves as a combustion chamber, and into one end of which leads a pipe 8 for gas or other suitable fuel.' Between the contiguous ends of the cylinder 1 and the hearth 7 is a housing 9, which is fitted accurately to both but is stationary and receives from the cylinder 1 as it rotates the iron sponge produced 'therein by the action of the heat generator in the combustion chamber 7 upon the mixture of iron ore and coal or coke in the cylinder 1. This housing 9 has a discharge aperture 10 in its bottom, through which the iron sponge falls as it arrives at that point. If the sponge is to be introduced i immediately into a furnace and used in the production of iron or steel as heretofore mentioned, it maybe received in a hopper 11 as it falls through the discharge opening 10, and discharged from time to time into cars 12 or other receptacles and conducted directly to the furnace in which it is to be used. In this exam le of the apparatus I have shown such a fhrnace in the form of an electric furnace 13 of the usual or any suitable type, the construction of which is Well understood and need not be described in detail. In` the reduction of pig iron in such a furnace a arge quantity of gas is evolved and this is utilized in heating the iron ore and carbonaceous material in the cylinder 1, by

.conducting it from the electric furnace through any suitable flue or iiues 14, 15, 16 back to the inlet pipe 8 of combustion chamber 7. This inlet pipe 8, if desired, may also lead directly from any suitable gas producer 17 for supplying the combustion chamber 7, should the gas from the electric furnace be insufficient. 'lhe electric furnace is shown with a stack 1,8, having a damper or valve 19, so that if desired the gases may be allowed to discharge directly into the atmosphere. 'lhe flue 14, 15,` is shown with an exhauster 20 to assist in drawing the gases from the electric furnace and-forcing them into the combustion chamber 7.

The mixture of ore and coke or coal may be fed into the upper end of the rotating cylinder 1 by any suitable means directly, if desired, or they may be passed through any suitable preheating device, as, for example, a substantially horizontal passage or chamber 21, in which is arranged an endless conveyer 22 driven continuously, or as desired, by any suitable means and discharging into the upper end of the cylinder 1, from which the waste .gases and heat rise into the chamber '21 and surround and heat the material progressing gradually to the inlet of the cylinder 1 on the conveyer 22.

According to the usual methods of manufacturing pig iron in blast furnaces, from 2,000 to 2,500 pounds of a good grade of coke and about 1200 pounds of limestone are required for every ton of iron manufactured, While by means of my improved method the same result may be accomplished by the use of this Waste product, i. e., coal dust or coke dust, and about only onefourth in quantity of that is required, and the limestone heretofore required is entirely unnecessary, although a small uantity for iiuxing purposes might be use if desired without increasing the expense. It is apparent, however, that a flux is not essential when roceeding according to my method,

since t ere does not exist in my method the` necessity for reducin the material to a molten condition, While that condition is essential in the production' ofiron in an ordinary blast furnace because otherwise the product could not be successfully Withdrawn. It is also obvious that my described method reduces the cost of production in the matter of labor, since the operation is performed by mechanical means and the material is advanced automatically from its crude state to a state of sponge ready for use in the electric or other furnace without handling.

This application is a division of my apphcation Serial No. 361,632, filed March 9th,

1907, containing claims to the method of facture of iron which consists in forming a {.twe subscribing,r Witnesses, 011 this eighth inixture 0f flue lulst' uul (-.ummlnuted cari day of July A. l). 1907. )onaeeeus matarla su )jeeting t 1e same to n n v v, :1- redueing degree of heat to produce iron HMM L' HAR u. blhlx 5 sponge, and finally eol'npressing such sponge. Witnesses:

In testimony whereof I have signed my i Il. E. SMITH, name to this specification, in the presence of WM. Il. BROWNRIGG. 

